Kardashian was born on October 21, 1980 in Los Angeles, California, the daughter of Robert and Kris (née Houghton). She has an older sister, Kourtney, a younger sister, Khloé, and a younger brother, Rob. Their mother is of Dutch, English, Irish, and Scottish ancestry, while their Father was a third-generation Armenian-American. After their parents divorced in 1991, her mother married again that year, to Caitlyn Jenner (then Bruce), the 1976 Summer Olympics decathlon winner. Through their marriage, Kardashian gained step-brothers Burton "Burt", Brandon, and Brody; step-sister Casey; and half-sisters Kendall and Kylie Jenner.

She attended Marymount High School, a Roman Catholic all-girls school in Los Angeles. In 1994, her Father represented football player O. J. Simpson during his murder trial. Simpson is Kardashian's godfather. Kardashian's Father died in 2003 of cancer. In her 20s, Kardashian was the close friend and Stylist of socialite Paris Hilton, through whom she first garnered media attention.

In 2000, 19-year-old Kardashian eloped with music Producer Damon Thomas. Thomas filed for divorce in 2003. Kardashian later credited their separation to physical and emotional abuse on his part. Prior to the completion of her divorce, Kardashian began dating singer Ray J.

In 2006, Kardashian entered the Business world with her two sisters and opened the boutique shop D-A-S-H in Calabasas, California. In 2007, Kardashian and three partners Brian Lee, Robert Shapiro and MJ Eng founded ShoeDazzle, an online shoe and accessories website. The site now boasts more than 3 million customers, who pay a monthly fee for access to a personalized selection of shoes, jewelry and handbags every month. The site also landed a $40-million investment from the venture capital firm Andreessen Horowitz. The company is valued at $280 million as of 2012. In March 2009, she launched an endorsement with her company, ShoeDazzle shopping, of which she is the co-founder and chief fashion Stylist. She then endorsed multiple other projects including a vanilla cupcake mix flavor called 'Va-Va-Va-Nilla' for the bakery, Famous Cupcakes.

In February 2007, a sex tape made by Kardashian and Ray J in 2003 was leaked. Kardashian filed a lawsuit against Vivid Entertainment, who distributed the film as Kim K Superstar. She later dropped the suit and settled for a reported US$5 million. In October 2007 Kardashian, in addition to her mother Kris Jenner, her step-parent Caitlyn Jenner (Bruce), her siblings Kourtney, Khloé, and Rob Kardashian, and half-sisters Kendall and Kylie Jenner, began to appear in the reality television series Keeping Up with the Kardashians. The series proved successful for E!, and has led to the creations of spin-offs including Kourtney and Kim Take New York and Kourtney and Kim Take Miami. In one of the episodes, Kim discussed an offer from Playboy to appear nude in the magazine. That December, Kardashian posed for a nude pictorial for Playboy.

In 2008, she made her feature film debut in the disaster film spoof Disaster Movie, in which she appeared as a character named Lisa. That same year, she was a participant on season seven of Dancing with the Stars, where she was partnered with Mark Ballas. Kardashian was the third contestant to be eliminated. In January 2009, Kardashian made a cameo appearance during an episode of the sitcom How I Met Your Mother, in the episode "Benefits". In April, she released a workout DVD series through her television production company Kimsaprincess Productions, LLC which has seen the release of three successful workout videos, Fit in Your Jeans by Friday, with trainers Jennifer Galardi and Patrick Goudeau. Kardashian played Elle in four episodes of the television series Beyond the Break.

That same month, Kardashian was involved in a lawsuit against one of her endorsements. Sanford Siegal, the creator of the Cookie Diet, sued Kardashian, claiming she defamed him on Twitter. According to Siegal, Kardashian tweeted in October 2009 that he was "falsely promoting" that she was on the cookie diet. Siegal filed a claim in a Florida state court charging that her statements were false and defamatory. He also alleged that Kardashian was on QuickTrim's payroll when she posted the tweet. Kardashian's tweet appears to stem from an article on CookieDiet.com, that named Kardashian as one of many celebrities who saw positive results on the diet. Kardashian sent a cease-and-desist order to Siegal, demanding the link be removed.

Beginning in early 2010, Kardashian and her sisters designed and developed clothing lines for Bebe stores and 'Virgins, Saints, and Angels'. In April 2010, Kardashian and her sisters released a sunless tanner "Kardashian Glamour Tan", that month. In October 2011, Kardashian and her sisters opened their Kardashian Khaos store in Las Vegas. In November 2012, Kardashian and her sisters internationally launched the 'Kardashian Kollection' in England, as well as launching a line of cosmetics, 'Khroma Beauty'.

In May 2011, Kardashian became engaged to NBA player Kris Humphries, then of the New Jersey Nets, whom she had been dating since October 2010. They were married in a wedding ceremony on August 20 in Montecito, California. Earlier that month, she had released her "wedding fragrance" called "Kim Kardashian Love" which coincided with her own wedding. A two-part TV special showing the preparations and the wedding itself aired on E! in early October 2011, amidst what The Washington Post called a "media blitz" related to the wedding. After 72 days of marriage, she filed for divorce from Humphries on October 31, citing irreconcilable differences. Several news outlets surmised that Kardashian's marriage to Humphries was merely a publicity stunt, to promote the Kardashian family's brand and their subsequent television ventures. A man professing to be her former publicist, Jonathan Jaxson, also claimed that her short-lived marriage was indeed staged and a ploy to generate money. Kardashian filed suit against Jaxson, saying his claims were untrue, and subsequently settled the case which included an apology from Jaxson. A widely circulated petition asking to remove all Kardashian-related programming from the air followed the split. The divorce was subject to widespread media attention.

In March 2012, Kardashian debuted her fourth fragrance, titled "True Reflection", which she worked with the company Dress for Success to promote. That month, Kardashian and her sisters were named in a $5 million class action lawsuit against QuickTrim, the weight loss supplement they endorse. The complaint, filed in the United States District Court for the Southern District of New York, accuses the Kardashians (along with QuickTrim's manufacturer, Windmill Health Products; the retailer GNC; and others in the sales and marketing chain) of false and deceptive marketing of the diet aid. The plaintiffs, hailing from several states, brought claims under their respective states' consumer protection laws. In April, E! renewed Keeping Up with the Kardashians for two additional seasons, in a deal reported to be worth $50 million. In October 2012, Kardashian released her fifth fragrance, "Glam", which "draws on the glamour of her Hollywood lifestyle", and was made available through Debenhams. In summer of 2012, Kardashian and her family filmed a music video in the Dominican Republic to Notorious B.I.G's song "Hypnotize".

Kardashian began dating Rapper and longtime friend Kanye West in April 2012, while still legally married to Humphries. Her divorce was finalized on June 3, 2013, while Kardashian gave birth to her first child with West, daughter North West, on June 15, 2013. Kardashian and West became engaged on October 21, Kardashian's 33rd birthday, and married on May 24, 2014 at Fort di Belvedere in Florence, Italy. Her wedding dress was designed by Riccardo Tisci of Givenchy with some guests' dresses designed by designer Michael Costello. In April 2015, Kardashian and West traveled to the Armenian Quarter of the Old City in Jerusalem to have their daughter, North, baptized in the Armenian Apostolic Church. The ceremony took place at the Cathedral of St. James. Khloe Kardashian was appointed the godmother of North. Kardashian gave birth to her second child, son Saint West, on December 5, 2015. The couple's high status and respective careers have resulted in their relationship becoming subject to heavy media coverage; The New York Times referred to their marriage as "a historic blizzard of Celebrity."

As of May 2014, Kardashian was estimated to be worth US$45 million. In 2015, Forbes reported she had "made more this year than ever as her earnings nearly doubled to $53 million from 2014's $28 million," and reported that she "has monetized fame better than any other." Much of her income include wholesale earnings of the Sears line, the Kardashian Kollection, which raked in $600 million in 2013 and the Kardashian Beauty cosmetics line, Kardashian-branded tanning products, the boutique-line DASH, as well as sponsored Instagram and Twitter posts which are collectively worth $10,000-25,000 per post.

In April 2015, she traveled to Armenia with her husband, her sister Khloé, and her daughter North and visited the Armenian Genodice memorial Tsitsernakaberd in Yerevan. In April 2016, Kardashian wrote an article on her website condemning The Wall Street Journal for running an advertisement denying the Armenian Genocide. During an interview with GQ for the July 2016 issue, Kardashian described herself as a Liberal Republican, fiscally conservative but socially progressive.

On October 2, 2016, while attending Paris Fashion Week, Kardashian was robbed at gunpoint in the apartment where she was staying. Five individuals, dressed as police officers, bound and gagged her, then stole $10 million worth of jewelry. The thieves got in her residence by threatening the concierge. Once they accessed Kardashian's room, they held a gun to her head, tying her wrists and legs and wrapping duct tape around her mouth as a gag. Kardashian, who was placed in the bathtub, was physically unharmed and reportedly begged for her life. She managed to wriggle her hands free from the plastic ties around her wrists and scream for help. The thieves escaped. On October 6, 2016, it was revealed that filming for the next season of Keeping up with the Kardashians had been placed "on hold indefinitely" after the robbery. Production resumed on October 26. Kardashian postponed a makeup demonstration in Dubai due to the incident.

The couple's third child, a daughter, was born via surrogate on January 15, 2018. On January 19, 2018, her name was announced as Chicago West.